import sys
def parse_inp():
    return tuple(map(lambda x: int(x), input().split(' ')))

def pour(cur, cap, frm, to):
    cur = list(cur)
    old = cur[to]
    cur[to] = min(cap[to], cur[frm]+cur[to])
    cur[frm] -= cur[to] - old
    return tuple(cur)

cap = parse_inp()
start = parse_inp()
end = parse_inp()

visited = {start: 0}
q = [start]
while len(q) > 0:
    top = q.pop(0)
    if top == end:
        print(visited[top])
        sys.exit()
    for i in range(3):
        for j in range(3):
            config = pour(top, cap, i, j)
            if not config in visited:
                visited[config] = visited[top] + 1
                q.append(config)

print(-1)